Photographic coupler compositions and methods for reducing continued coupling
US5298368A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 23, 1991 |
| Grant date | Mar 29, 1994 |
| Priority date | — |
| Expiry date | Apr 23, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C7/3885
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Photographic coupler compositions comprise (a) a pyrazolone magenta dye-forming coupler compound, and (b) a sulfoxide compound in an amount sufficient to reduce continued coupling of the coupler compound during the bleach step of a color photographic process. The sulfoxide compound is of the formula ##STR1## wherein R.sub.1 and R.sub.2 are individually selected from the group consisting of straight and branched chain alkyl groups, alkenyl groups and alkylene groups; straight and branched chain alkyl groups, alkenyl groups and alkylene groups containing at least one substituent selected from the group consisting of alkoxy, aryloxy, aryl, alkoxycarbonyl, aryloxycarbonyl, acyloxy, carbonamido and carbamoyl groups and halogen atoms; a phenyl group; and a phenyl group containing at least one substituent selected from the group consisting of alkyl, alkoxy, aryloxy, aryl, alkoxycarbonyl, aryloxycarbonyl, acyloxy, carbonamido and carbamoyl groups and halogen atoms. Additionally, R.sub.1 and R.sub.2 combined contain at least 12 carbon atoms. Preferably, the coupler composition is substantially free of phenol compounds when R.sub.1 and R.sub.2 are other than unsubstituted alkyl, alkenyl or a…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.